1. Field of the Invention
The invention is directed to a straw chopper arrangement for a combine having a rotor with an approximately vertical axis of rotation. The rotor is provided with at least one impeller blade extending radially outward from the hub. Flails are pivotally mounted to the outermost end of the impeller blade from the hub. The flails on each impeller blade are vertically spaced apart from one another. The flails interact with counter knives or shear bars attached to the chopper housing where the shear bars are located in the intervening spaces between the flails.
2. Description of the Prior Art
Straw chopper arrangements are applied to agricultural combines and cut the straw remaining after the grain has been threshed and separated from the straw. Known chopper arrangements frequently consist of a chopper unit and a following distribution arrangement. The "Lexion" combine advertisement of the CLAAS company, printer's notice 7/96 200/190.406.8, shows a chopper unit with horizontal axis of rotation that is followed by two distribution blowers with vertical axes of rotation and separate outlet funnels. Since this chopper unit requires a large amount of installation space, it hinders access to the interior of the combine, in particular the sieves. In order to gain access to the sieves and to utilize an attached implement, the outlet funnels of the distribution blowers must be pivoted out of the way.
DE-OS-25-29 019 shows a straw chopper whose straw cutting tool contains one or more knife-carrying shafts having axes of rotation that are arranged vertically or approximately vertically. Fixed shear bars are arranged between the knife-carrying shafts. At the lower end of the knife-carrying shafts centrifugal disks with impeller blades are provided. The straw is conducted to the straw cutting tool over a slide. If the slide is pivoted aside the operation of the straw chopper is stopped and the straw is ejected directly without chopping. With this arrangement the operations of chopping and distribution cannot be selected independently of each other.
EP-A1-0 702 892 shows a straw chopper in which a chopper arrangement and a distributing arrangement are integrated into a single tool unit in a rotor housing. The tool unit forms a cutter and an impeller arrangement, so that the mixture of straw and chaff falling into the rotor housing is chopped and simultaneously conveyed in the direction of an output duct. The mixture of straw and chaff is supplied to the tool unit through a transfer funnel. Here too, the straw may be either chopped and distributed or it may be delivered without being chopped.